Electrophotographic marking is a well known and commonly used method of copying or printing original documents. Electrophotographic marking is performed by exposing a light image representation of a desired document onto a substantially uniformly charged photoreceptor. In response to that light image the photoreceptor discharges, creating an electrostatic latent image of the desired document on the photoreceptor's surface. Toner particles are then deposited onto the latent image to form a toner image. That toner image is then transferred from the photoreceptor onto a receiving substrate such as a sheet of paper. The transferred toner image is then fused to the receiving substrate. The surface of the photoreceptor is then cleaned of residual developing material and recharged in preparation for the production of another image.
Of the various electrophotographic printing processes mentioned above, this invention relates most generally to fusing the toner with the receiving substrate. While fusing has been performed in several ways, the most common method is to pass a toner-bearing substrate through a heated pressure nip. The combination of heat and pressure fuses the toner with the substrate. The heated pressure nip is often formed using a heated fuser roller, a pressure roller, and a conformable fuser belt that overlaps the fuser roller and that is disposed between the fuser roller and the pressure roller. When the toner-bearing receiving substrate passes between the fuser belt and the pressure roller, with the toner contacting the fuser belt, the toner is fused with the receiving substrate.
While heated pressure nips are successful, they have problems. One common problem is that the fused toner and the receiving substrate tend to stick to the fuser belt. A prior art approach to addressing the sticking problem is to use a small diameter fuser roller and/or a sharp fuser belt turn. The resulting sharp turn tends to separate the fused toner-substrate from the fusing system. Another approach is to coat the surface of the fuser belt with a release agent, thereby reducing the fuser belt's surface tension and reducing sticking. Yet another method of addressing the sticking problem is to use an elastic belt. Unfortunately, these methods are insufficient in some applications. Therefore, a new way of addressing the sticking problem would be beneficial.